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    <title>Document</title>
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<body>
    <script>
        /* Boolean() */
        /* c */
        /* 
          ""  NaN undefined null 0-->false
         */
        var a=10;
        var b=0;
        var c="hello"
        console.log(Boolean(a));
        console.log(Boolean(b));
        console.log(Boolean(c));
        console.log(Boolean(""));
        console.log(Boolean(0));
        console.log(Boolean(null));
        console.log(Boolean(NaN));
        console.log(Boolean(undefined));

    </script>
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